Reliance Jio Infocomm has announced another network-sharing deal with Reliance Communications (RCOM) in a further sign of improving relations between India’s Ambani brothers.

The so-called Master Service Agreement will give Reliance Jio (Mumbai, India) access to RCOM’s (Mumbai, India) nationwide inter-city fiber network, which it hopes will help to speed up its deployment of a 4G network across India.

Reliance Jio said the agreement was based on “arm’s length pricing at prevailing market prices”.

RCOM’s fiber network is said to extend to nearly 500,000 kilometers across more than 300 cities and towns across the country.

The latest tie-up comes after the two operators signed an inter-city optic fiber sharing agreement in April 2013 and a tower-sharing agreement in August 2013.

The first of those deals took observers by surprise given the frosty relations up to then between Anil Ambani, the owner of RCOM, and his brother Mukesh, who controls Reliance Jio.

In 2005, the two brothers had agreed to divide up the business empire their father had built, with reports suggesting they were barely on speaking terms before coming together last year.

Mukesh, however, is desperate to make a play in the Indian market for high-speed broadband services delivered over 4G networks, but lacks the infrastructure needed to roll out services quickly.

Besides teaming up with brother Anil, he has also struck deals with tower companies Bharti Infratel (Gurgaon, India) and Viom Networks (Gurgaon, India), and in December signed a network-sharing deal with Bharti Airtel (New Delhi, India) – one of the country’s biggest mobile operators.